The invention relates to electrical circuit arrangements and more specifically to electrical circuit arrangements for use in measuring the time taken to achieve a required change in frequency.
There are many applications where a frequency producing arrangement (e.g. a frequency synthesizer in radio communications apparatus) is required to make very rapid changes in frequency between two specific frequency values. It is not possible in practice for such changes to take place instantaneously and it is therefore important to know, e,g, in testing and setting up such frequency producing arrangements, the time taken for a specific frequency change to be achieved, such as, for example, for the output frequency to be not more than a specified (relatively small) number of Hertz away from the required final value.